Weeds Act - Frequently Asked Questions

Table of Contents

Why does Ontario have the Weed Control Act?

The intent of the Weed Control Act is to reduce:

  1. The infestation of noxious weeds that negatively impact on the industries of agriculture and horticulture.
  2. Plant diseases by eliminating plant disease hosts such as common barberry and European buckthorn.
  3. Health hazards to livestock caused by poisonous plants.

How do I contact my local area or municipal weed inspector?

Your local municipality, region, district or county can provide you with contact information for the Weed Inspector or local by-law enforcement officer for your area.

What is a noxious weed?

A noxious weed includes a plant that has been listed in the schedule of noxious weeds found in regulation 1096 made under the Weed Control Act. This list is commonly referred to as the "Noxious Weed List". The council of the municipality may, subject to the approval of the Minister, designate additional plants as local weeds through a by-law made in accordance with section 10 of the Weed Control Act. These local weeds are deemed to be noxious weeds in the area where the by-law applies.

In general, a species designated as a noxious weed under the Weed Control Act is one that:

  • Is difficult to manage on agricultural land once established and will reduce the yield and quality of the crop being grown;
  • Negatively affects the health and well-being of livestock; or
  • Poses a risk to the health and well-being of agricultural workers.

In Ontario, 25 weeds are designated as noxious under the Weed Control Act. A list of these weeds can be found on the Ministry's website.

What recent amendments have been made to the Schedule of Noxious Weeds?

Effective immediately, dog-strangling vine and black dog-strangling vine have been added to the noxious weed list while milkweed has been removed.

Since it was originally added to the Schedule of Noxious Weeds, more management options for farmers to deal with common milkweed have been developed.

Dog-strangling vine and black dog-strangling vine are aggressive, invasive plants that can interrupt the monarch butterfly's life cycle. The monarch butterfly is attracted to the plants, but any eggs laid will not survive. Adding these weeds to the Schedule of Noxious Weeds will also provide another tool for weed inspectors to control these non-native plants to minimize interference with agriculture or horticulture.

Please refer to Chapter 18, page 402, in OMAF/MRA Publication 75, Guide to Weed Control for information on management strategies for dog-strangling vine.

Can I plant milkweed in my garden?

Gardeners and concerned citizens are encouraged to be responsible when using native milkweed plants to provide a habitat for monarch butterflies. A variety of milkweed – such as swamp milkweed – is less likely to spread and interfere with agriculture. Planting milkweed next to farmers' fields is not recommended.


For more information:
Toll Free: 1-877-424-1300
Local: (519) 826-4047
E-mail: ag.info.omafra@ontario.ca

Author: Mike Cowbrough, Weed Management Field Crops Program Lead/OMAF
Creation Date: 22 March 2005
Last Reviewed: 18 June 2014